The use of vertical silos for the curing and storing of silage for livestock feed is well known. Silos have been built of wooden staves, concrete staves, tile, cement blocks and other materials for a long period of time.
Modern silos sometimes use vitreous linings in an upright silo. Other types of silage storing devices have also recently become more popularly used. Bunker silos, for example, include those formed with earthen or concrete walls bordering a broad trench. In effect, the upright silo is laid on its side. Because silage needs to cure essentially without being exposed to air, the key to the successful bunker silo is the use of an impervious plastic cover, which may also be used as a lining.
Also, the use of graineries and various bin arrangements for corn and grain is known. Occasionally, these materials are piled and covered.